The present invention relates to a surgical instrument, in particular, a surgical instrument for driving a bone plug into a hole formed in a bone for securing a ligament to the bone.
Artificial materials such as artificial ligaments and reinforcement meshes, or organic materials such as patella bone-tendon, hamstring muscle, and fascia lata are used for anterior cruciate ligament reconstructions. In early stages of the reconstruction surgery, the reconstruction ligament was fixed to the bone using an anchor bolt, for example. Today, the artificial ligament is fixed to the bone by inserting it into a hole formed in the bone, or bone tunnel, and then closing the bone tunnel with a bone chip, an interference screw, or an inner button. Such methods for fixing ligaments, however, do not provide a stable joint between the ligament and the bone, but the joint tends to become loose.
Recently, a new ligament fixing method is developed which provides more stable joint between the ligament and the bone by fixing the reconstruction ligament inserted in the bone tunnel by means of a bone plug. Japanese Patent application provisional publication H9-10245 discloses an example of such bone plugs made from bio-compatible material, such as calcium phosphate compound, formed in a hollow cylindrical shape having a hole extending along its center axis.
The bone plug is driven into the bone tunnel using a driving-instrument. Since the bone plug is driven into the bone inside a living body, e.g. inside the knee joint, the bone plug is hardly kept in a right attitude at a right position of the driving-instrument during the surgery, which in turn results in a rather long operation time. Accordingly, a surgical instrument is required that facilitates the plugging of the bone plug into the bone.